Overexpression of phosphatidylinositol transfer protein β in NIH3T3 cells has a stimulatory effect on sphingomyelin synthesis and apoptosis

Tiel, Claudia M. van; Schenning, Martijn; Snoek, Gerry T.; Wirtz, K.W.A.

doi:10.1016/j.bbalip.2003.08.009

Cited by 12 publications

(22 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These, as yet unidentified secreted factors demonstrate autocrine as well as paracrine activity and most probably belong to the family of endocannabinoids [12][13][14]. Increased expression of PI-TPb in mouse fibroblast cells increased the duration of the cell cycle and made these cells highly susceptible towards induction of apoptosis by UV-light or TNFa [15]. Finally, studies with intact animals produced interesting data.…”

Section: Introductionmentioning

confidence: 86%

“…These results suggest the involvement of phosphorylation of PI-TP in the cellular relocalization. Metabolic labeling of mouse fibroblast cells with 32 P-anorganic phosphate enabled the detection of phospho-PI-TPa but failed to show phospho-PITPb because of the very low cellular concentration of PI-TPb [15,18,25]. Using cells with increased expression of PI-TPb and the use of very sensitive detection methods also allowed observation of the in vivo phosphorylation of PI-TPb [19].…”

Section: Phosphorylation Of Pi-tpa and Pi-tpb In Vitro And In Vivomentioning

confidence: 99%

“…In wild type mouse fibroblast cells, the level of PI-TPb is too low to enable dependable studies on phosphorylation or cellular localization [15]. Mouse fibroblast cells with a 10-15-fold increased expression of PI-TPb (SPIb cells) showed significantly different physiological properties when compared to the wild type mouse fibroblast cells [15,36]:…”

Section: In Vivo Phosphorylation Of Pi-tpbmentioning

confidence: 99%

“…Mouse fibroblast cells with a 10-15-fold increased expression of PI-TPb (SPIb cells) showed significantly different physiological properties when compared to the wild type mouse fibroblast cells [15,36]:…”

Section: In Vivo Phosphorylation Of Pi-tpbmentioning

confidence: 99%

“…It is not clear whether actual lipid transfer is involved in the physiological function of PI-TPa or PI-TPb or how the binding/exchange of PI/PC/SM is established or regulated. Single or multiple phosphorylation of the two PI-TP isoforms has been described and it has been shown that this phosphorylation is a regulatory factor for to the specific cellular localization, the lipid ligands bound and several of the cellular functions of the PI-TPs investigated [15,18,19].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Structure–function relationships of phosphatidylinositol transfer proteins: involvement of phosphorylation sites

2004

View full text Add to dashboard Cite

The mammalian low molecular weight phosphatidylinositol transfer proteins: PI-TPa and PI-TPb are extremely well conserved and highly homologous. Surprisingly, the two proteins clearly show different cellular localizations and display contrary physiological functions. Phosphorylation of the proteins might be the regulatory factor to ensure the selective cellular functions. A major difference between PI-TPa and PI-TPb is the capacity of PI-TPb to bind and transfer sphingomyelin (SM) in vivo. This activity is correlated with phosphorylation of Ser262, which is only present in PI-TPb. Structural aspects of phosphorylation sites of PI-TPs are analyzed in order to find an explanation for the functional data. We propose that phosphorylation of one serine residue (Ser165/166) in both PI-TPa and PI-TPb is involved in the regulation of membrane binding of all PI-TPs and that phosphorylation of the unique Ser262 in PI-TPb-like proteins ensures the right cellular localization of PI-TPbs that is necessary for the specific activity at the Golgi membrane.

show abstract